Because it looks (equally predictably) rubbish. No need to defend trash, it's not like Merlin actually care about this other than making easy money.
They know they can pay for nothing, do a half arsed job and people will still go along with it.
Most the criticism of it I've seen online has been done with humour of disbelief anyway. You don't have to like everything by default for fear of being seen as "negative".
True there's always some who will complain regardless, but just look at this. Seeing how people will defend the rubbish being fed them by Merlin (they're capable of better, look at Wicker Man), more because they have something against people's opinions than because they actually like the attraction being made, is sadder in my opinion. If they made anything entertaining and original, I'd be all over it in positivity!